Metal powder injection molding (MIM) technology can directly forming high precision and complex geometry, small
parts, and wide applicable materials. After introduced into China since the 1970’s, it has been rapidly developing in all
walks of life.
Metal powder injection molding in the earlier application in the ordnance production in China, which mainly includes
firearms, artillery shells and other components. Gun parts shape and structure is complex, due to special application
environment and has a certain risk, determine the gun parts must have high quality, including mechanical properties,
density, precision, etc. Traditional gun parts generally used forging blank as raw material production by machining, the
machining can obtain pretty high quality of gun parts. But machining material utilization rate is low, especially in the
production of gun structure parts, metal shell, etc., the utilization rate of material only between 15% to 20%, most of the
materials are cut. And for small parts of guns (trigger, magazine catch, etc.), high strength material (carbon steel, etc.)
production difficulty is big, the efficiency is low and is not economical.
Use a metal injection molding forming can make all kinds of complex shape parts, and overcome the machining
characteristics of low material utilization, can save a lot of metal materials, greatly reduce the processing cost. Because the
metal injection molding has a variety of advantages, people began to use the process to produce all kinds of gun parts, for
example, the main spring housing, hammer, trigger, magazine catch, inadequate safety, etc. With the development of
metal injection molding and mature technology, metal powder injection parts occupies more and more proportion in the
gun composition.
At present, the rifle in the ordnance, in addition to the big parts like gun body and gunstock, most of the rest metal parts is
made by metal injection molding. In the pistol, charging, trigger and shell also use the injection molding parts. Metal
injection molding has wide range of materials application, can produce all kinds of metal materials of gun parts, satisfy
people demand of variety of materials on the application of the gun.
In addition, the quality of gun parts produced by MIM have good consistency and high density, and has the characteristics
of less machining, most of the parts don’t need to be machined and can reach the accuracy of requirement, this makes the
metal powder injection parts occupies a considerable proportion in guns.
